SPANX-WORMS. Wr is, 
The caterpillar, a little longer than one inch and a half 
when mature, is a typical spanning—or measuring-worm, 
which tapers considerably towards the front. It is of a yel- 
lowish-green color, with an indistinct whitish line down 
the back, and a rather broad whitish streak on each side 
below the spiracles, bordered above 
with faint purple, which increases 
in depth of color on the posterior 
segments and becomes a _ purple 
stripe on the last one. Thespiracles 
: are white, edged with purple; each 
Hieienean ee Susie Sen ment. Ol the. body. has the an- 
Pat eat terior portion swollen and yellow- 
ish, and on most of the segments are a few minute black 
dots. 
The caterpillar forms a slight cocoon inside the space of 
a leaf, the edges of which have been drawn together for this 
purpose. The pupa is of a dark olive-green color, witha 
pale-greenish abdomen and a row of black dots down the 
back and another one on each side. The imago appears in 
about a fortnight; it is shown in Fig 180. 
Being a general feeder, the insect, though quite common, 
does not often occur in sufficient numbers on cultivated 
plants to become destructive. Yet the writer has seen cases 
where large patches of currants had lost their entire foliage 
on account of these worms. In fact we can never say with 
any assurance that an insect of this kind will not most un- 
expectedly and suddenly multiply to such an extent that it 
becomes a veritable pest. Another geometer, usually very 
uncommon, in fact almost unknown, became so destructive 
in 1898 as to defoliate the wild gooseberry plants over 
many square miles. It is the Diastictis (Thamnonoma) 
Havicaria Pack. As the moths vary considerably a number 
of them are shown in Fig. 181, Plate XVIJi. 
